(function (doc, win) {
    // eslint-disable-next-line one-var
    var docEl = doc.documentElement,
      resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
      recalc = function () {
        var clientWidth = docEl.clientWidth
        if (clientWidth >= 375) {
          clientWidth = 375
        }
        if (!clientWidth) return
        docEl.style.fontSize = 100 * (clientWidth / 375) + 'px'
      }
    if (!doc.addEventListener) return
    win.addEventListener(resizeEvt, recalc, false)
    doc.addEventListener('DOMContentLoaded', recalc, false)
  })(document, window)